JP6458953B2 - Hydrogel adhesion method - Google Patents

Description

  In the present invention, a liquid hydrogel-forming composition is interposed between a gel surface to which one hydrogel is to be bonded and a gel surface to which the other hydrogel is to be bonded. It is related with the method of adhering.

In recent years, hydrogels have attracted attention from the viewpoint of a soft material material that has a high biocompatibility and a low environmental load because water is the main component. As a constituent component of hydrogel, water-soluble polymers such as polyacrylamide, polyacrylic acid, and polyvinyl alcohol are widely used. Above all, the composite hydrogel composed of two components of polyacrylamide-based or cross-linked polyethylene glycol-based water-soluble polymer and clay mineral-based inorganic fine particles has succeeded in increasing the strength of the hydrogel and has greatly expanded its range of use. (Patent Document 1 and Patent Document 2). Recently, a highly versatile organic-inorganic composite hydrogel that can be produced simply by mixing clay mineral inorganic fine particles, an aqueous dispersant, and a polyacrylate has also been reported (Non-patent Document 1).
Hydrogel has a very wide range of uses such as medical, quasi-drugs, cosmetics, daily necessities, food, electronic materials, agricultural materials, building materials, toys, hygiene products, bio-based materials, etc. Is processed, formed and used. As a processing method of the self-supporting hydrogel, in addition to producing a gel in a mold or extrusion molding, unnecessary portions such as cutting and die cutting can be cut out and formed. However, in the production of hydrogels that require complex shapes, these operations are very difficult or complicated. From the viewpoint of work efficiency, a method of assembling and producing fine parts by bonding is simple. Furthermore, adhesion is very convenient for repairing damaged parts such as cracks and breaks of already completed hydrogel molded products. Thus, a hydrogel bonding method is desired.
As a method for adhering hydrogels, there has been known a method of constructing a polymer network by immersing a reactive monomer in an adhesive surface and polymerizing reaction after adhering the adhesive surfaces to each other (Non-patent Document 2). . Also known is a method of adhering opposing ionic gels such as between a polyanion and a polycation by electrostatic interaction (Non-Patent Document 3). Furthermore, as a method for bonding the same ionic gels, a method of bonding via opposing ionic fine particles is known (Patent Document 3). Recently, hydrogels having self-healing properties have also been reported (Patent Document 4).

JP 2002-053629 A Japanese Patent No. 4704506 JP 2010-6855 A International Publication No. 2011/001657 Pamphlet

Proceedings of the 61st Annual Meeting of the Society of Polymer Science, Vol. 61, no. 1, p. 683 (2012) Abstracts of 17th Polymer Gel Research Conference, p. 29 (2006) January 18 Bull. Chem. Soc. Jpn., 2002, 75, 383.

However, the bonding method disclosed in Non-Patent Document 2 is complicated and low in versatility. Further, the bonding method disclosed in Non-Patent Document 3 is electrostatically repelled, so that it is impossible to bond gels composed of the same composition components. Furthermore, the bonding method disclosed in Patent Document 3 can be used only for gels having ionic properties, and it is difficult to bond a gel made of a neutral polymer such as polyacrylamide or polyvinyl alcohol. Moreover, in the hydrogel disclosed in Patent Document 4, the dendrimer that is a constituent component of the hydrogel is produced by a multi-step synthesis reaction, and thus there is a problem that the production cost is high.
Then, this invention is made | formed in view of the said situation, and it aims at providing the method of adhere | attaching hydrogels easily by use of an inexpensive raw material.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have made a hydrogel by interposing a hydrogel-forming composition between the hydrogel surface to be bonded and the hydrogel surface and then gelling. The inventors have found that they are strongly bonded to each other, and completed the present invention.
That is, as a first aspect, the present invention is a method for adhering the same or different types of hydrogels, and includes a gel surface to which one of the hydrogels is to be bonded and a gel surface to which the other hydrogel is to be bonded. The present invention relates to a method for adhering a hydrogel, comprising interposing a liquid hydrogel-forming composition between them and joining the surfaces of both gels to be bonded together.
As a second aspect, the hydrogel has a water-soluble organic polymer (A), a silicate (B), and a silicate dispersant (C) having an organic acid structure, an organic acid salt structure or an organic acid anion structure. It is related with the adhesion method of the hydrogel as described in a 1st viewpoint which is a hydrogel containing.
As a third aspect, the hydrogel-forming composition has an organic acid structure, an organic acid salt structure or an organic acid anion structure, a water-soluble organic polymer (A), a silicate (B), and a dispersant for the silicate. It is related with the adhesion method of the hydrogel as described in a 1st viewpoint or a 2nd viewpoint which is a hydrogel formation composition containing (C).
As a fourth aspect, the hydrogel adhesion method according to the second aspect or the third aspect, wherein the water-soluble organic polymer (A) is a water-soluble polymer having a carboxylic acid structure, a carboxylate structure, or a carboxyanion structure. About.
As a fifth aspect, the present invention relates to the hydrogel adhesion method according to the fourth aspect, in which the water-soluble organic polymer (A) is a water-soluble completely neutralized or partially neutralized polyacrylate.
As a sixth aspect, the present invention relates to the hydrogel adhesion method according to the fifth aspect, wherein the water-soluble organic polymer (A) is a completely neutralized or partially neutralized polyacrylate having a weight average molecular weight of 1,000,000 to 10,000,000.
As a seventh aspect, the hydrogel is a hydrogel containing another water-soluble organic polymer (A ′) and a silicate (B), according to any one of the first aspect or the third to sixth aspects. The present invention relates to a method for bonding hydrogels.
As an eighth aspect, in the seventh aspect, the water-soluble organic polymer (A ′) is one or more selected from the group consisting of polyacrylamide, crosslinked polyethylene glycol, and acrylamide / acrylic acid ester copolymer. It relates to a method for adhering the described hydrogel.
As a ninth aspect, the present invention relates to the hydrogel adhesion method according to the eighth aspect, in which the water-soluble organic polymer (A ′) is poly (N-isopropylacrylamide) or poly (N, N-dimethylacrylamide).
As a tenth aspect, the present invention relates to the hydrogel adhesion method according to any one of the second to ninth aspects, wherein the silicate (B) is a water-swellable silicate particle.
The eleventh aspect relates to the method for adhering a hydrogel according to the tenth aspect, in which the silicate (B) is water-swellable silicate particles selected from the group consisting of smectite, bentonite, vermiculite, and mica.
As a twelfth aspect, the hydrogel adhesion method according to the eleventh aspect, wherein the dispersant (C) is a dispersant for the water-swellable silicate particles.
As a thirteenth aspect, the dispersant (C) is sodium orthophosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium tetraphosphate, sodium hexametaphosphate, sodium polyphosphate, sodium poly (meth) acrylate, poly (meth) acrylic acid. Ammonium, sodium acrylate / sodium maleate copolymer, ammonium acrylate / ammonium maleate copolymer, sodium hydroxide, hydroxylamine, sodium carbonate, sodium silicate, polyethylene glycol, polypropylene glycol, sodium humate and lignin sulfone It is related with the adhesion | attachment method as described in a 12th viewpoint which is 1 type, or 2 or more types chosen from the group which consists of sodium acid.

As described above, according to the present invention, hydrogels can be easily and strongly bonded to each other using a commercially available raw material. In addition to repairing a hydrogel that has been broken or cracked, it is possible to bond arbitrary portions together, and this can be used as a new gel processing method.
Further, according to the present invention, the hydrogel to be bonded can be bonded to the same type or different types.
Furthermore, while hydrogel is a promising material as a soft material with a low environmental load, it has problems such as difficulty in complicated processing and inability to use due to breakage, but such a problem is the bonding method of the present invention. Therefore, the effect of increasing the utility value of the hydrogel is expected.

FIG. 1 is a graph showing the relationship between the strain rate and the stress until breakage of the adhesive gel measured in Example 3.

The present invention is a method for adhering the same or different types of hydrogels, wherein a liquid hydrogel-forming composition is formed between the surface of the gel to which one of the hydrogels is to be bonded and the surface of the gel to which the other hydrogel is to be bonded. The present invention relates to a method for adhering a hydrogel comprising the steps of interposing an object and joining both gel surfaces to be bonded.
The hydrogel-forming composition for adhering the hydrogel of the present invention is prepared from a water-soluble organic polymer (A), a silicate (B) and a dispersant (C) of the silicate. Immediately after mixing these components, it is paste-like and fluid, and the liquid is adhered to the adhesive surface of the hydrogel to be bonded and then bonded. The hydrogel-forming composition can be used after diluting with water in order to further improve the fluidity.
The hydrogel bonding method of the present invention can be applied not only when two or more hydrogels are bonded to each other, but also when the tear or broken part is bonded in the repair of a crack or broken part generated in the hydrogel. is there.

[Hydrogel]
The hydrogel bonded by the bonding method of the present invention is preferably a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure, a silicate (B), and the silicate. It is a hydrogel containing a dispersing agent (C), or a hydrogel containing another water-soluble organic polymer (A ′) and a silicate (B).
In addition to the said component, you may mix | blend other components arbitrarily with the said hydrogel as needed in the range which does not impair the desired effect of this hydrogel.

<Component (A): Water-soluble organic polymer having organic acid structure, organic acid salt structure or organic acid anion structure>
Component (A) is a water-soluble organic polymer having an organic acid structure, an organic acid salt structure, or an organic acid anion structure.
Examples of the water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure include those having a carboxyl group, such as poly (meth) acrylate, carboxyvinyl polymer salt, carboxy Methylcellulose salts; those having a sulfonyl group; polystyrene sulfonates; those having a phosphonyl group include polyvinylphosphonates. Examples of the salt include sodium salt, ammonium salt, potassium salt, lithium salt and the like. In the present invention, (meth) acrylic acid refers to both acrylic acid and methacrylic acid.

  The water-soluble organic polymer (A) may be crosslinked or copolymerized, and either a completely neutralized product or a partially neutralized product can be used.

The water-soluble organic polymer (A) has a weight average molecular weight of preferably 1,000,000 to 10,000,000, more preferably 2,000,000 to 7,000,000 in terms of polyethylene glycol by gel permeation chromatography (GPC).
The water-soluble organic polymer available as a commercial product preferably has a weight average molecular weight described in the commercial product of 1 million to 10 million, and more preferably a weight average molecular weight of 2 million to 7 million.

  The water-soluble organic polymer (A) preferably has a carboxylic acid structure, a carboxylate structure or a carboxy anion structure, and is particularly preferably a water-soluble completely neutralized or partially neutralized polyacrylate. Specifically, sodium polyacrylate is preferable, and non-crosslinked highly polymerized sodium polyacrylate having a weight average molecular weight of 2 million to 7 million and completely or partially neutralized is particularly preferable.

  The content of the water-soluble organic polymer (A) is 0.01% by mass to 20% by mass, preferably 0.1% by mass to 10% by mass in 100% by mass of the hydrogel.

<Component (A '): Water-soluble organic polymer>
The component (A ′) is a water-soluble organic polymer different from the water-soluble organic polymer (A), and may be crosslinked or copolymerized.
Examples of the water-soluble organic polymer (A ′) include polyacrylamide, crosslinked polyethylene glycol, and acrylamide / acrylic acid ester copolymer. These water-soluble organic polymers (A ′) may be used alone or in combination of two or more.
Among them, the water-soluble organic polymer (A ′) is preferably polyacrylamide, and particularly preferably poly (N-isopropylacrylamide) and poly (N, N-dimethylacrylamide).

  Moreover, about the weight average molecular weight and content of water-soluble organic polymer (A '), above-mentioned <component (A): water-soluble organic polymer which has organic acid structure, organic acid salt structure, or organic acid anion structure> It is as described in.

<Component (B): Silicate>
The silicate (B) is preferably water-swellable silicate particles.
Examples of the silicate (B) include smectite, bentonite, vermiculite, and mica, and those that form a colloid using water or a water-containing solvent as a dispersion medium are preferable. The smectite is a group name such as montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, and the like.
Examples of the primary particle shape of the silicate particle include a disk shape, a plate shape, a spherical shape, a granular shape, a cubic shape, a needle shape, a rod shape, and an amorphous shape, and a disk shape or a plate shape having a diameter of 5 nm to 1000 nm. Is preferred.

  Preferable specific examples of the silicate (B) include layered silicate. As an example that can be easily obtained as a commercial product, Laponite manufactured by Rockwood Additives (LAPONITE, Rockwood Additives) (Registered trademark) XLG (synthetic hectorite), XLS (synthetic hectorite, containing sodium pyrophosphate as a dispersing agent), XL21 (sodium magnesium fluorosilicate), RD (synthetic hectorite), RDS (synthetic hectorite, dispersing agent) As inorganic polyphosphate), and S482 (synthetic hectorite, containing dispersant); Lucentite (Corp Chemical Co., Ltd.) SWN (synthetic smectite) and SWF (synthetic smectite), Micromica (Synthetic mica) and somasif (co Puchemical Co., Ltd. registered trademark, synthetic mica); Kunipia Co., Ltd. Kunipia (Kunimine Industry Co., Ltd. registered trademark, Montmorillonite), Smecton (Kunimine Industry Co., Ltd. registered trademark) SA (Synthetic Saponite); Hojun Co., Ltd. Bengel ( Hojun registered trademark, natural bentonite refined product) and the like.

  The content of the silicate (B) is 0.01% by mass to 20% by mass, preferably 0.1% by mass to 15% by mass in 100% by mass of the hydrogel.

<Component (C): Silicate Dispersant>
The silicate dispersant (C) is preferably a dispersant of water-swellable silicate particles.
As the silicate dispersant (C), a dispersant or a peptizer used for the purpose of improving the dispersibility of the silicate or delaminating the layered silicate can be used.
Examples of the silicate dispersant (C) include, for example, sodium orthophosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium tetraphosphate, sodium hexametaphosphate, sodium polyphosphate; As a dispersant, sodium poly (meth) acrylate, poly (meth) ammonium acrylate, sodium acrylate / sodium maleate copolymer, ammonium acrylate / ammonium maleate copolymer; water acting as an alkali, water Sodium oxide, hydroxylamine; sodium carbonate, sodium silicate; those that react with polyvalent cations to form insoluble or complex salts; other organic peptizers such as polyethylene glycol, polypropylene glycol, sodium humate Potassium and sodium lignin sulfonate and the like.
Preferably, a phosphate type dispersant, a carboxylate type dispersant, and other organic peptizers are used. Here, the carboxylate-based dispersant preferably has a weight average molecular weight of 1,000 to 20,000.
Specifically, sodium pyrophosphate as a phosphate dispersant, sodium polyacrylate having a weight average molecular weight of 1000 to 20,000 as a carboxylate dispersant, and polyethylene glycol (PEG 900, etc.) as other organic peptizers preferable.

  Low-polymerized sodium polyacrylate having a weight average molecular weight of 1000 to 20,000 interacts with silicate particles to generate negative charges derived from carboxyl anions on the surface of the particles and disperses silicates by repulsion of charges, etc. It is known to act as a dispersing agent by the mechanism.

The content of the dispersant (C) is 0.001% by mass to 20% by mass, preferably 0.01% by mass to 10% by mass in 100% by mass of the hydrogel.
In preparing a hydrogel containing a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure, a silicate (B) and a dispersant (C) of the silicate, When a silicate containing a dispersant is used as the component (B), the component (C) dispersant may or may not be added.

  In addition, the hydrogel intercalates between the layers of the layered silicate and promotes peeling, and monohydric or polyhydric alcohols such as methanol, ethanol, glycol, formamide, hydrazine, dimethyl sulfoxide, urea, acetamide , And potassium acetate can be added.

  The hydrogel containing a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure, a silicate (B) and a dispersant (C) for the silicate includes (Clay minerals), water dispersants, and those formed from compositions containing polyacrylates are preferred, while hydrogels containing other water-soluble organic polymers (A ′) and silicates (B) include Those formed from a composition comprising a silicate (clay mineral) and poly (N-isopropylacrylamide) or cross-linked polyethylene glycol are preferred.

[Hydrogel-forming composition]
The hydrogel-forming composition for adhering the hydrogel of the present invention is obtained by mixing a water-soluble organic polymer (A), a silicate (B) and a dispersant (C) of the silicate. After mixing, the liquid before gelation sufficiently proceeds is applied to the hydrogel adhesive surface. The hydrogel-forming composition can be used even if the components and composition ratios of the hydrogel to be bonded are different. Further, in order to lower the viscosity of the hydrogel-forming composition and improve the coating property, it can be used by diluting with water. The dilution of the hydrogel-forming composition with water can be carried out by adding a predetermined amount of water to the pasty substance at the time of mixing or after mixing the components and mixing them.

  As a preferable combination of the water-soluble organic polymer (A), the silicate (B), and the silicate dispersant (C) in the hydrogel-forming composition, 100 mass% of the hydrogel-forming composition , 0.1 to 10% by mass of completely neutralized or partially neutralized non-crosslinked sodium polyacrylate having a weight average molecular weight of 2 to 7 million as component (A), and water-swellable smectite as component (B) Alternatively, 0.1 mass% to 15 mass% of saponite and 0.01 mass% to 10 mass% of sodium pyrophosphate as the component (C) or 0.01 mass% to 10 mass% of polyacrylate having a weight average molecular weight of 1000 to 20000 %. The amount of water used to dilute the hydrogel-forming composition is up to 10 times, preferably up to 3 times as a volume ratio to the hydrogel-forming composition.

<Method for producing hydrogel-forming composition>
A hydrogel containing a water-soluble organic polymer (A), a silicate (B), and a dispersant (C) of the silicate includes a composition containing components (A) to (C) and water as needed. Is obtained by mixing.
It can be made to gel by mixing a mixture of the two components of the composition or an aqueous solution or aqueous dispersion thereof with the remaining one component or an aqueous solution or aqueous dispersion thereof. Gelation is also possible by adding water to the mixture of components.
As a method of mixing the components in the composition, ultrasonic treatment can be used in addition to mechanical or manual stirring, but mechanical stirring is preferable. For mechanical stirring, for example, a magnetic stirrer, propeller stirrer, rotation / revolution mixer, disper, homogenizer, shaker, vortex mixer, ball mill, line mixer, kneader, ultrasonic oscillator, etc. can be used. it can.
The mixing temperature is the freezing point or boiling point of the aqueous solution or aqueous dispersion, preferably -5 ° C to 100 ° C, more preferably 0 ° C to 50 ° C.

  A hydrogel containing a water-soluble polymer (A ′) and a silicate (B) can be produced by a method described in JP-A-2002-53629.

<Hydrogel adhesion method>
Immediately after the production of the hydrogel-forming composition, it is in the form of a paste, but if left as it is, gelation proceeds to increase the viscosity and decrease the adhesion ability. Therefore, after preparing a hydrogel-forming composition, it is immediately used for adhesion of hydrogel. Moreover, since it is difficult to store the mixed hydrogel-forming composition for a long time, the time until use after preparation is preferably within 10 hours, more preferably within 3 hours.
As a method of interposing the hydrogel-forming composition between the gel surface to which one hydrogel is to be bonded and the gel surface to which the other hydrogel is to be bonded, the hydrogel-forming composition is to be bonded to both the hydrogels. There is no particular limitation as long as it can be interposed between the gel surfaces. Applying a hydrogel-forming composition to one or both of the gel surfaces, and spraying the hydrogel-forming composition to one or both of the gel surfaces And the formation of a hydrogel-forming composition layer on one or both of the gel surfaces. Among them, from the viewpoint of ease of operation, hydrogel is applied to one or both surfaces of the hydrogel to be bonded. It is preferable to apply a formable composition.

The hydrogel bonding method of the present invention interposes and attempts to bond a hydrogel-forming composition between the surface of the gel to which one of the hydrogels is to be bonded and the surface of the gel to which the other hydrogel is to be bonded. It can adhere | attach by joining both gel surfaces.
There is no limitation on the surface of the gel to which the hydrogel is to be bonded, such as cut surfaces or fresh surfaces that have not been cut, and the hydrogel used in the hydrogel bonding method of the present invention may be the same type of hydrogel or a different type of hydrogel. Good.
Furthermore, the hydrogel bonding method of the present invention is applicable not only when two or more hydrogels are bonded to each other, but also when the tears or broken parts are bonded in the repair of a tear or broken part generated in the hydrogel. Is possible.

The amount of the hydrogel-forming composition interposed between the gel surface to which one hydrogel is to be bonded and the gel surface to which the other hydrogel is to be bonded is 0.001 to 1 g / cm ² , preferably 0. 0.01 to 0.5 g / cm ² .
The temperature at the time of joining is −5 ° C. to 100 ° C., preferably around 20 ° C., specifically 18 ° C. to 25 ° C.
The standing time after joining is preferably 1 hour to 72 hours, more preferably 24 hours to 48 hours.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to the following Example.
<Production Example 1: Production of 9% Laponite XLG aqueous dispersion>
Low-polymerized sodium polyacrylate (Julimer AC-103: manufactured by Toagosei Co., Ltd., weight average molecular weight 6000) 7.5 parts, urea 3 parts (made by Junsei Chemical), phenoxyethanol 0.5 parts (made by Junsei Chemical), water 74 The parts were mixed and stirred at 25 ° C. until a homogeneous solution was obtained. 9 parts of Laponite XLG (manufactured by Rockwood Additives) was added little by little, and after uniformly dispersing, 3 parts of a 10% aqueous solution of citric acid (manufactured by Junsei Kagaku) was added. While the mixture was vigorously stirred, the temperature was raised to 80 ° C., and stirring was continued at 80 ° C. for 30 minutes. The mixture was stirred while cooling to 25 ° C. in an ice water bath, 3 parts of a 10% aqueous solution of citric acid (manufactured by Junsei Kagaku) was added, and the mixture was vigorously stirred for 1 hour to obtain the desired product.

<Production Example 2: Production of 1.5% sodium polyacrylate aqueous solution>
3 parts of urea (manufactured by Junsei Kagaku), 0.5 part of phenoxyethanol (manufactured by Junsei Kagaku) and 95 parts of water were mixed and stirred at 25 ° C. until a homogeneous solution was obtained. While vigorously stirring, 1.5 parts of highly polymerized sodium polyacrylate (Viscomate NP-800: Showa Denko KK) was added little by little. Vigorous stirring was continued at 25 ° C. until the highly polymerized sodium polyacrylate was completely dissolved (about 5 hours) to obtain the desired product.

<Production Example 3: Production of hydrogel>
The 9% Laponite XLG aqueous dispersion produced in Production Example 1 and the 1.5% sodium polyacrylate aqueous solution produced in Production Example 2 were mixed at a volume ratio of 1: 2, and a rotating / revolving mixer (manufactured by Sinky Corporation) ARE-310) was stirred at 25 ° C. and 2000 rpm for 5 minutes and then allowed to stand for 3 days to obtain a hydrogel.

[Example 1: Production of hydrogel-forming composition]
The 9% Laponite XLG aqueous dispersion produced in Production Example 1, the 1.5% sodium polyacrylate aqueous solution produced in Production Example 2, and water were mixed at a volume ratio of 1: 2: 1 and stirred vigorously at room temperature for 1 minute. Thus, a hydrogel-forming composition was obtained. The produced hydrogel-forming composition was used for adhesion of the hydrogel within 3 hours.

[Example 2: Adhesion of hydrogel]
A cylindrical hydrogel having a diameter of 1.2 cm and a length of 5 cm was produced by the production method of Production Example 3, and then cut into a length of 2.5 cm. 0.2 mL of the hydrogel-forming composition produced in Example 1 was applied to the cut surface, the hydrogels were bonded together, and allowed to stand for 48 hours.

[Example 3: Tensile breaking strength test of adhesive gel]
The hydrogel bonded under the conditions of Example 2 was measured for tensile strength at break using a creep meter RE2-30005B manufactured by Yamaden Co., Ltd. In the measurement, a tension adapter (Yamaden Plunger Tensile Chuck, No. 12, Model P-12) was used. The bonded hydrogel was stretched at a speed of 1 mm / second, and the strain rate and stress until breakage were measured. The measurement results are shown in FIG.

  According to the present invention, hydrogels can be easily bonded to each other using a commercially available raw material. As a result, the hydrogel product that has been broken or cracked can be repaired, and any location can be bonded to each other. Therefore, formation by assembly is possible, and it can be used as a new gel processing method. Hydrogel is a promising material as a soft material with a low environmental load, but it has had problems such as difficulty in complicated processing and inability to use due to damage. However, since these problems are solved by the bonding method of the present invention, an effect of increasing the utility value of the hydrogel is expected.

Claims (13)

  A method for adhering the same or different types of hydrogels, wherein a liquid hydrogel-forming composition is interposed between the surface of the gel to which one of the hydrogels is to be bonded and the surface of the gel to which the other hydrogel is to be bonded. And bonding the surfaces of the gels to be bonded together.   The hydrogel is a hydrogel comprising a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure, a silicate (B), and a dispersant (C) of the silicate. The method for adhering a hydrogel according to claim 1.   The hydrogel-forming composition comprises a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure or an organic acid anion structure, a silicate (B), and a dispersant for the silicate (C). The method for adhering a hydrogel according to claim 1 or 2, which is a hydrogel-forming composition.   The method for adhering a hydrogel according to claim 2 or 3, wherein the water-soluble organic polymer (A) is a water-soluble polymer having a carboxylic acid structure, a carboxylate structure or a carboxy anion structure.   The hydrogel adhesion method according to claim 4, wherein the water-soluble organic polymer (A) is a water-soluble completely neutralized or partially neutralized polyacrylate.   The method for adhering a hydrogel according to claim 5, wherein the water-soluble organic polymer (A) is a fully neutralized or partially neutralized polyacrylate having a weight average molecular weight of 1,000,000 to 10,000,000.   The method for adhering a hydrogel according to any one of claims 1 or 3 to 6, wherein the hydrogel is a hydrogel containing another water-soluble organic polymer (A ') and a silicate (B). .   The hydrogel adhesion according to claim 7, wherein the water-soluble organic polymer (A ') is one or more selected from the group consisting of polyacrylamide, crosslinked polyethylene glycol, and acrylamide / acrylic acid ester copolymer. Method.   The method for adhering a hydrogel according to claim 8, wherein the water-soluble organic polymer (A ′) is poly (N-isopropylacrylamide) or poly (N, N-dimethylacrylamide).   The method for adhering a hydrogel according to claim 2, wherein the silicate (B) is water-swellable silicate particles.   The method for adhering a hydrogel according to claim 10, wherein the silicate (B) is water-swellable silicate particles selected from the group consisting of smectite, bentonite, vermiculite and mica.   The method for adhering a hydrogel according to claim 11, wherein the dispersant (C) is a dispersant for the water-swellable silicate particles.   The dispersant (C) is sodium orthophosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium tetraphosphate, sodium hexametaphosphate, sodium polyphosphate, sodium poly (meth) acrylate, ammonium poly (meth) acrylate, sodium acrylate / Sodium maleate copolymer, ammonium acrylate / ammonium maleate copolymer, sodium hydroxide, hydroxylamine, sodium carbonate, sodium silicate, polyethylene glycol, polypropylene glycol, sodium humate and sodium lignin sulfonate The adhesion method according to claim 12, which is one or more selected from the group consisting of:

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